The present invention relates to a battery charger for use in electrically charging batteries, and more specifically to a battery charger which includes a plurality of fuel cell modules which provide a charging current for substantially maintaining the charge of the battery, and a controller which delivers the charging current to the battery under predetermined operational conditions.
In assorted commercial and industrial applications, uninterruptible power supplies are necessary in order to maintain crucial systems in an operational state notwithstanding the loss of a primary electrical power source. For example, navigation sites; communication repeater sites; mission critical computer systems; and even railroad crossing signals must be fully operational 24 hours a day in order to prevent injuries, accidents, or interruptions in industrial and commercial processes or business operations.
Heretofore, user""s desiring to have uninterruptible power supplies for critical or mission essential operations have typically utilized battery banks and/or stand-by generator sets which provide electrical power upon the interruption of the primary AC power source.
Typically these uninterruptible power supplies which have battery banks include a charging assembly which maintains the battery or bank of batteries in a fully charged state so that they may be ready to deliver electrical power upon an interruption of the primary power source.
While this arrangement has worked with some degree of success, it has several shortcomings which have detracted from its usefulness. One of the chief problems with this type of uninterruptible power supply is that the charging assembly utilized to maintain a battery bank in a fully charged condition often receives it""s power from the primary electrical power source that normally serves the load. As a result, if the primary power source is interrupted, the charging assembly no longer provides a charging current to the batteries. Consequently, if the battery bank is called upon to deliver power over a prolonged period of time, and without a charging assembly providing an electrical current to recharge the batteries, the battery bank often becomes deeply discharged. Those skilled in the art will recognize that batteries that are often cycled through deep electrical discharges often experience shortened operational lifetimes. Still further, another shortcoming in this same arrangement, is that a charging assembly can occasionally malfunction with the result that the current capacity of the battery bank becomes degraded.
As will be recognized, in extremely critical industrial, commercial or other applications, this may be a completely intolerable situation.
A battery charger which addresses these and other perceived shortcomings in the prior art practices is the subject matter of the present application.
A first aspect of the present invention relates to a battery charger for use with a battery and which is provided with a first charging current to substantially maintain the electrical charge of the battery and which includes, a plurality of fuel cell modules which provide a second charging current for substantially maintaining the charge of the battery; and a controller electrically coupled with the plurality of fuel cell modules, and wherein upon interruption of the first charging current, the controller operably delivers the second charging current to the battery.
Another aspect of the present invention relates to a battery charger for use with a battery and which is provided with a first charging current which is supplied by way of an AC to DC converter which is electrically coupled with an AC power source, the battery charger including a housing defining a cavity and which further includes an air plenum which is coupled in fluid flowing relation relative to the cavity; an electrical bus borne by the housing and which is positioned in the cavity of the housing; a source of a fuel gas coupled in fluid flowing relation relative to the cavity; a plurality of fuel cell modules which, when rendered operational, produce a second charging current for substantially maintaining the electrical charge of the battery, and heat energy, and wherein the plurality of fuel cell modules are received within the cavity of the housing and are individually electrically coupled with the electrical bus and disposed in fluid flowing relation relative to the source of fuel gas, and wherein the individual fuel cell modules may be electrically decoupled from the electrical bus and removed from the housing while the remaining fuel cell modules continue in operation; an air movement assembly borne by the housing and which is coupled in fluid flowing relation relative to the air plenum, and wherein the air plenum delivers a cathode air stream by way of the air plenum and which removes a preponderance of the heat energy generated during operation of the plurality of fuel cell modules; a controller borne by the housing and which is controllably electrically coupled with the plurality of fuel cell modules, the electrical bus and the air movement assembly, and wherein the controller is electrically coupled with the AC power source, and is further disposed in controlling relation relative to the source of fuel gas; and a communications device electrically coupled to the controller and which is responsive to an electrical signal sent from a remote location, and wherein the controller operably delivers the second charging current to the battery upon interruption of the AC power source.
Yet another aspect of the present invention relates to a method of charging a battery, and which includes providing a source of AC power; providing an AC to DC converter and supplying the source of AC power to the AC to DC converter to produce a first charging current; supplying the first charging current to maintain the charge of the battery; providing a plurality of fuel cell modules, which when rendered operable, produces a second charging current; providing a controller which is electrically coupled with the AC power source, and which is further disposed in controlling relation relative to the plurality of fuel cell modules; and delivering the second charging current to the battery when the controller senses interruption of the AC power source.